It sounds like this might be a “triple net” lease in which the tenant is expected to pay taxes, insurance, and maintenance. It wouldn’t be uncommon for the landlord to foot you with the entire bill, but it would be worth investigating how the landlord paid the taxes. If they are paying quarterly or monthly, then it’s probably a negotiating point that you’ll pay your share accordingly. Keep in mind that if all the tenants paid a full year’s taxes, but the landlord paid monthly, there’s the possibility the landlord could take the huge chunk of tenant tax money, but default on paying the taxes. Your space could end up in jeopardy through no fault of your own.
It might be worthwhile to get your accountant and/or attorney to look at your lease and simply write a letter that you’ll pay taxes according to the same payout the landlord uses.